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PubMed2005

Prevalence of Trichomonas gallinae in northern goshawks from the Berlin area of northeastern Germany.

In recent years, the northern goshawk (Accipiter gentilis) has colonized suburban and urban areas in Berlin, Germany, and elsewhere in Europe. Because of the high proportion of feral pigeons (Columba livia f. domestica) in their diet, urban goshawks are suspected to have a high infection rate with Trichomonas gallinae. Therefore, from 1998 to 2001, we examined 269 nestlings from 90 nests for infection with T. gallinae by culture of swabs taken from the oropharynx and checked their oropharynx for the presence of caseous lesions indicative of trichomonosis. In 80% of the nest sites (n=90), at least one nestling was infected. The nestling infection rate with T. gallinae was 69.7% (n=33) in 1998, 73.0% (n=89) in 1999, 55.8% (n=77) in 2000, and 62.9% (n=70) in 2001. In total, 65.1% of the northern goshawk nestlings were culture positive for T. gallinae. Prevalence increased with the age of nestlings (chi2=12.4, n=269, df=5, P=0.03) and tended to increase with brood size (chi2=9.345, n=269, df=4, P=0.053). Caseous lesions were present in 12 nestlings (4.5%), but only 10 of these were culture positive for T. gallinae. Two nestlings (0.7%) had large caseous lesions (diameter>1 cm) characteristic of late-stage trichomonosis and died shortly after examination. It is suggested that the combination of a high prevalence of T. gallinae with a low rate of pathologicic changes is the result of an evolutionary-adapted parasite-host relationship.

Age Factors↗

PubMedDate not supplied

[The interrelation of microbial ecosystems and human immunity].

An analytical survey of literature on the problem of the study of interrelations between the immune status of the organism and microbial ecology of a man is presented. The criteria which characterize normal flora of human organism varying in the process of evolutionary adaptation, interaction with microorganism and response of the immune system, its participation in formation of protective functions of the organism are considered. It is shown that the proceeding character and the finite result of different infectious processes depend on the state of the organism immune system. A possibility of correction of certain immunological indices with the help of representatives of normal microflora has been considered. A conclusion has been made on the necessity to solve the problem of infectious diseases and complications in a complex of microbiological and immunological investigations.

Bacteria↗

PubMed2000

Simple sequence repeats in Escherichia coli: abundance, distribution, composition, and polymorphism.

Computer-based genome-wide screening of the DNA sequence of Escherichia coli strain K12 revealed tens of thousands of tandem simple sequence repeat (SSR) tracts, with motifs ranging from 1 to 6 nucleotides. SSRs were well distributed throughout the genome. Mononucleotide SSRs were over-represented in noncoding regions and under-represented in open reading frames (ORFs). Nucleotide composition of mono- and dinucleotide SSRs, both in ORFs and in noncoding regions, differed from that of the genomic region in which they occurred, with 93% of all mononucleotide SSRs proving to be of A or T. Computer-based analysis of the fine position of every SSR locus in the noncoding portion of the genome relative to downstream ORFs showed SSRs located in areas that could affect gene regulation. DNA sequences at 14 arbitrarily chosen SSR tracts were compared among E. coli strains. Polymorphisms of SSR copy number were observed at four of seven mononucleotide SSR tracts screened, with all polymorphisms occurring in noncoding regions. SSR polymorphism could prove important as a genome-wide source of variation, both for practical applications (including rapid detection, strain identification, and detection of loci affecting key phenotypes) and for evolutionary adaptation of microbes.

Base Composition↗

PubMed2000

CpG motifs for optimization of DNA vaccines.

The immunogenicity of DNA vaccines is due in part to the presence of stimulatory CpG motifs, which may actually be essential to their function. CpG motifs are unmethylated cytosine-guanine dinucleotides within a certain flanking base context and such sequences are commonly found in bacterial but not mammalian DNA. It appears that through evolutionary adaptation, the vertebrate immune system developed the ability to recognize these sequences as a "danger signal" and respond by rapid activation of the innate immune system. This innate activation synergizes with signals mediated through antigen receptors, and thus also augments antigen-specific responses. Other sequences, known as "neutralizing" motifs, which can counteract stimulatory CpG motifs, are also found in DNA vaccines. The immunogenicity of a DNA vaccine may depend on the balance between stimulatory and neutralizing motifs, and if so, their efficacy might be improved through the removal of neutralizing motifs and addition of species-specific stimulatory CpG motifs.

Adjuvants, Immunologic↗

PubMed2002

Discovery of immunostimulatory CpG-DNA and its application to tuberculosis vaccine development.

DNA containing an unmethylated CpG motif has a potent immunostimulatory effect on the vertebrate immune system. Because such CpG motifs are relatively common in bacterial DNA, but rare in mammalian animal and plant DNA, they may be an evolutionary adaptation augmenting innate immunity, most likely in response to pathogens that replicate within the host cells, such as viruses and intracellular bacteria. Microbial infection induces innate immunity by triggering pattern-recognition systems. The infected cells produce proinflammatory cytokines that directly combat microbial invaders and express costimulating surface molecules, which develop adaptive immunity by inducing distinct T cell differentiation. Bacterial DNA with unmethylated CpG-DNA stimulates vertebrate immature immune cells to induce maturation and to produce TNF-alpha as well as Th1-type cytokines, IL-12 and IFN-gamma. Therefore, CpG-DNA functions as an adjuvant for regulating the initiation of Th1 differentiation. The roles of immunostimulatory CpG motifs in DNA vaccine developments and in therapeutic applications have been discussed.

Adjuvants, Immunologic↗

PubMed2002

Developmental basis of limb evolution.

Can developmental processes account for vertebrate limb homology, the overall similarity of definitive limb structure despite differences in different taxa which often relate to evolutionary adaptations? Relevant evidence is from molecular studies, from 'cut & paste' experimental embryology and from classical descriptive accounts of embryology and structure. There is striking evidence of a similar pattern of homologous regulatory gene expression (eg Shh, and Hox A & D genes) in tetrapod limb buds, and both similarity and differences when these are compared with expression patterns in a teleost fish paired fin bud. But these findings are as yet from too few tetrapod species (chick and mouse) to permit a 'molecular bauplan' for the limb to be proposed with any certainty. Further, the identification of similar networks of regulatory genes common to non-homologous developmental systems limits possibilities for finding a basis for classical structural homology in terms of expression of system-specific genes or gene networks. An integrated approach is needed, combining evidence from the fin-limb transition, and from study of the patterns and processes of amphibian and avian limb embryology, and this points towards a conserved developmental bauplan for the pentadactyl skeleton of the type earlier proposed by Alberch. Key features include the digital arch, restriction of digit number to a maximum of 5 and stereotyped connections between prechondrogenic condensations. But this is a dynamic and not rigidly fixed bauplan. It has no single set of skeletal elements (except proximally), since the position of joint formation in the prechondrogenic condensations is not stereotyped. Urodele amphibians in particular demonstrate heterochronic differences in the timing of events. Heterochrony may underlie some of the important changes in the pentadactyl pattern during evolution.

Animals↗

PubMed1956

The shoulder joint; observations on comparative anatomy, physiology and treatment.

In a visual study of human and simian function of the shoulder joint, manifest superiority of the latter was noted. Comparative anatomical studies tend to confirm these observations and indicate that many common affections of the shoulder in humans may stem from incomplete evolutionary adaptation. Certain anatomical clues may lead to improvements in conservative and surgical treatment.A regimen of conservative and operative treatment developed over a period of many years has been found to be clinically effective for the relief of chronic refractory shoulder pain. These techniques differ at many points from present practices of a majority of physicians who deal with diseases of the shoulder.

Anatomy, Comparative↗

PubMed1992

Evolution of intestinal apolipoprotein B mRNA editing. Chicken apolipoprotein B mRNA is not edited, but chicken enterocytes contain in vitro editing enhancement factor(s).

Mammalian intestinal apolipoprotein B (apoB) messenger RNA (mRNA) undergoes posttranscriptional editing, changing codon 2153 from CAA in apoB100 mRNA to an in-frame translational stop codon (UAA) in apoB48 mRNA. By contrast, chicken intestinal apoB cDNA contains a CAA codon at the corresponding site and apoB mRNA from chicken enterocytes, kidney, and liver is unedited. The cDNA sequence of chicken apoB spanning the edited base is divergent from mammalian apoB cDNA sequence, with 70% homology over the conserved 29-nucleotide sequence (6662-6690) flanking codon 2153. Efficient in vitro editing of both human and rat, but not chicken, synthetic apoB RNA was achieved using rat enterocyte S-100 extracts. By contrast, chicken enterocyte S-100 extracts failed to edit chicken, rat, or human synthetic apoB RNA. Mixing experiments, however, revealed that chicken enterocyte S-100 extracts enhance the in vitro editing activity of rat, pig, and human enterocyte S-100 extracts upon homologous RNAs. The editing enhancement activity of chicken enterocyte S-100 extracts is tissue-specific, heat-sensitive, substrate-saturable, and sensitive to proteinase K, but resistant to micrococcal nuclease. The activity was partially purified by Q-Sepharose chromatography and has an average molecular mass of 49 kDa when analyzed by gel filtration chromatography. We conclude that the evolutionary adaptation of intestinal apoB mRNA editing requires both a requisite RNA motif and tissue-specific factors which mediate the site-specific modification.

Animals↗

PubMed2003

Empathy, communication, deception.

Empathy is understood as a mode of understanding operating on a subconscious level of mental processing. The cognitive element can only abstractly be distinguished from its affective expression. When recognizing a fellow creature we involuntarily sympathize with it. Recognition of covert motivations of overt behavior is the first step in formation of a communication channel between two (or more) empathizing agents. Yet, since communication evolved in variably complex social environments it was subject to pressure of conflicting individual interests. Deception thus evolved as an adaptive evolutionary strategy. Empathic understanding does not necessarily entail recognition of agent's real intentions. Deception may be achieved on both conscious and unconscious processing levels. A sufficient degree of biopsychosocial maturity must be reached for a child to be able to independently recognize verbal and non-verbal communication finesses. Once this level has been attained, the prevailing emotional orientation determines his/her degree of empathizing competence.

Communication↗

PubMed2003

[Localization of NADPH diaphorase in central nervous system of the chiton Leptochiton assimilis in normal conditions and during hypoxia].

By light and electron microscope histochemical and cytochemical methods, the localization and activity of NADPH-diaphorase (NADPH-d) were studied in the central nervous system (CNS) of the chiton in control and after hypoxia. After acute hypoxia, the enzymatic activity increased in all regions of CNS. At a chronic hypoxia, the activity of NADPH-d decreased to remain, however, higher than in control. Ultrastructural studies confirmed the availability of structural changes in neurons, and shifts in the activity of NADPH-d in control and in experimental mollusks. The elevated enzymatic activity revealed in this study may be due to the fact that these mollusks have been evolutionary adapted to a periodical oxygen deficiency.

Anaerobiosis↗

PubMed2004

Selective potentiation of proximal processes: neurobiological mechanisms for spread of activation.

BACKGROUND: Signal detection by one sense selectively activates other relevant systems. For example, when an auditory stimulus comes from a specific location, visual sensitivity, tactile sensitivity, and motor readiness increase for stimuli or actions in that direction. This observed phenomenon provides an apparent sensory-sensory and sensory-motor coordination with evolutionary adaptive advantages. Anatomically, many of the relevant cortical sites are adjacent to each other. MATERIAL/METHODS: The spread of excitation from an active processing site in the cortex to nearby functions can be seen in brain scans. Cognitive and affective functions also selectively activate each other and are activated by focal sensory stimulation based on cortical proximity. These behavioral interactions seem to offer no selective adaptability but still call for a model of possible mediation. The objective of the current paper is to consider evidence for competing mechanisms for the flow of cortical activation that are characterized by being neurobiologically feasible, showing preferential activation over short distances, and having empirical support. RESULTS: These three criteria are met by blood flow, heat flow, nearest networks, electromagnetism, and inhibition. CONCLUSIONS: It is suggested that several of these mechanisms work independently or synergetically to produce the known interactions among attention, affect, cognition, and behavior. An understanding of these processes and the functional cerebral space in which they operate can suggest practical applications for the manipulation of behavior.

Cerebrovascular Circulation↗

PubMed2005

[Wilhelm Troll (1897-1978). The tradition of idealistic morphology in the German botanical sciences of the 20th century].

During the first half of the 19th century, idealistic morphology developed into an influential research program in the German biosciences. This program was based on the concept of an ideal connection existing between various living beings. The growth of Darwinian thought and its new paradigm of historical explanation supplanted the idealistic morphology. Yet in the first half of the 20th century the principles of idealistic morphology experienced a powerful revival. Wilhelm Troll (1897-1978) was one of the most significant figures in this renaissance. Guided by the ideas of J.W. von Goethe, Troll established a research program rejecting causal, functional, and phylogenetic explanations as well as the idea of evolutionary adaptation. Instead, he attempted to create a 'pure' morphology based on the descriptions of various plant species. Governed by some explicitly metaphysical presumptions, Troll based his theory on the description of the organismal Gestalt. In consequence, his theory was actually a return to the proper idealistic morphology as it was known in the early 19th century. It lead German botanical morphology to a period of methodological and epistemological return.

Adaptation, Biological↗

PubMedDate not supplied

Surface morphology and characteristics of hemocytes of Biomphalaria glabrata (Pulmonata: Planorbidae) from two geographic sources.

Biomphalaria glabrata is a fresh water snail of medical importance since it is the intermediate host of the trematode Schistosoma mansoni. The internal defense system of mollusks is mostly represented by circulating elements of the hemolymph (hemocytes). The infectivity of S. mansoni to B. glabrata is determined by genetic factors and evolutionary adaptations. In the present work factors about the parasite/snail relationship were evaluated, especially those related to the morphology and characteristics of the surface of cells present in the hemolymph of two strains of B. glabrata: a strain with high susceptibility to S. mansoni (Puerto Rico, PR) and a strain with medium susceptibility (Caripe, Ca). Hemolymph was collected by cephalopodal puncture; a total and a differential count of hemocytes were done in dyed preparations and through scanning electron microscopy (SEM). Results from both strains show a high quantitative variability of the total hemocyte count. Hemocytes dyed with May-Grünwald Giemsa showed cells with a basophilic nucleus predominantly in PR (61.7%), dense and strongly basophilic in Ca (71.2%) with significant differences between them. Through SEM round cells with a corrugated surface were observed (6-10microm), hemocytes with an irregular spongy surface (12microm), others with many projections (16microm) and cells not reported in similar to erythrocytes (21microm). Hemocytic cells from both strains confirmed cytoadherence and encapsulation were confirmed in the hemocytic cells from both strains, while no differences associated to the susceptibility of the strains were observed after 2 h of parasite-hemocyte incubation.

Animals↗

PubMed1991

A biologic basis for limited Kupffer cell reactivity to portal-derived endotoxin.

Despite continuous exposure to gut-derived endotoxin (lipopolysaccharide) under normal conditions, Kupffer cells (KC) fail to generate detrimental cytokine responses. KC function within a unique microenvironment in which high hepatic arginase activities (25 times greater than those activities in the kidney) result in negligible local L-arginine levels. To evaluate the relevance of this profound arginine deficiency on the physiologic function of KC, the kinetics of tumor necrosis factor (TNF-alpha) production and autoregulatory eicosanoid prostaglandin E2 (PGE2) production were compared in lipopolysaccharide-stimulated KC cultured with (1200 mumol/L) and without (10 mumol/L) L-arginine media. In (+)arginine culture the KC TNF-alpha production peaked early before decreasing as PGE2 production increased. In (-)arginine culture, however, KC TNF-alpha production was significantly (p less than 0.01) reduced, whereas PGE2 production was amplified (p less than 0.01). When cyclooxygenase blockade with indomethacin completely prevented KC production of PGE2 in (-)arginine culture, TNF-alpha production was upregulated (p less than 0.001 vs (-)arginine; p not significant vs (+)arginine). These arginine-specific depression of TNF-alpha responses appeared unique to KC because both TNF-alpha and PGE2 levels increased when peritoneal, pleural, and alveolar macrophages were stimulated by lipopolysaccharide in (-)arginine medium. This PGE2-dependent autoregulation of potentially harmful lipopolysaccharide-induced TNF-alpha responses may reflect an evolutionary adaptation by KC to their local hepatic environment and strategic anatomic position in the portal circuit, which optimally removes endotoxin and naturally protects the host.

Animals↗

PubMed1991

Effect of diet on progression of chronic renal disease.

Changes in renal function induced by protein intake are thought to reflect evolutionary adaptation of the kidney. Excess dietary proteins over long periods may increase normal blood flow and glomerular filtration rate, requiring the continuous use of outer cortex's reserve glomeruli. According to the hyperfiltration theory, pressures and flows in outer cortical glomeruli contribute to continuous intrarenal capillary hypertension and predispose healthy people to progressive glomerular sclerosis and deterioration of renal function. Pressures and flows associated with the response to renal disease in turn may accelerate the development of sclerosis, leading to even more rapid loss of renal function. Restriction of dietary protein (less than or equal to 0.6 g/kg per day) and/or phosphorus seems to slow the rate of loss of renal function in patients with chronic renal insufficiency. Evidence for the role of lipids in the progression of renal disease is not clear. All of these dietary factors possibly play a role in the progression of renal disease; the relative importance of each factor varies, depending on the pathogenesis, stage, and mechanism of progression of the disease. Findings indicate that nutrition therapy can decrease rate of deterioration of renal function in patients with chronic renal diseases.

Animals↗

PubMed1990

Defeat-induced hypoalgesia in the rat: effects of conditioned odors, naltrexone, and extinction.

In Experiment 1, male rats were either defeated as a colony intruder by alpha conspecifics or had no defeat experience, and 24 hr later they were given a paw injection of formalin prior to observational tests with or without alpha-colony odors. The combination of defeat and tests with these odors produced conditioned hypoalgesia (i.e., a suppression in paw licking) and freezing. In Experiment 2, defeated rats were given either an injection of naltrexone or saline prior to defeat and 24 hr later prior to testing. An injection of naltrexone prior to defeat increased freezing during defeat and later testing. In contrast, naltrexone during testing did not affect freezing but significantly reduced hypoalgesia. In Experiment 3, a 12-hr exposure session with alpha-colony odors extinguished hypoalgesia in previously defeated rats. These findings are discussed in terms of associative, opioid/nonopioid, and adaptive evolutionary processes.

Animals↗

PubMed1989

[Ultrastructural changes in the neurons of the cerebral cortex of ondatra in acute hypoxia].

The reaction of cells in the sensomotor cortex of the ondatra cerebrum has been studied electron microscopically under acute hypoxia conditions. Certain changes have been revealed in neuronal bodies, dendrites, dendritic spines, as well as in synaptic contacts. Reaction of glial cells is noted. The degree of manifestation of the changes essentially varies in different neurons. In most cells, however, they are of reversible character, despite duration of the hypoxia effect. This is evidently connected with the fact, that the ondatra is a diving animal, which is evolutionary adapted to a periodical deficiency of oxygen. The neuronal changes revealed, nevertheless, are not the signs, specifically caused by hypoxia, they are peculiar for many other effects (deafferentation, influences of neurotoxins, stress etc.).

Acute Disease↗

PubMed1989

[Erysipelas as a disease factor].

The infection with Erysipelas rhusiopathiae demonstrates that it is possible to characterize the significance of predisposing factors. The virulence of the agent is most important among the exogenous factors; it determines decisively the course of the disease: 1. paracute course as septicemia; 2. chronic course as polyarthritis; 3. subclinical course nearly without any symptoms. The immune status and the genotype of the host are predominant out of endogenous factors. The importance of immunity is known since a long time. A series of field observations supported the potential genetical influence in the pig. Within the hereditability an association to the MHC (in special genetic lines of rats to the RT 1 system of the MHC) was most recently determined in inbred laboratory animals. Additionally several environmental conditions, which can be summarized as stress, and as endogenous factor the age of the animals are relevant for the pathogenesis of the erysipelas infection. A non variable but most important disposition for special tissues are the so-called "borderline tissues", where accumulation, sedimentation and persistence of bacterial antigens are wellknown as described earlier. This phenomenon is determined by hemodynamic manifestation and quantifiably regulated by cytokines especially interleukin (IL 1) as well as by the tumor necrosis factor (TNF alpha) and prostaglandin PgE2. Additionally the cross reactivity of antibodies of Erysipelas rhusiopathiae against most specific collagen of type II, IX and XI in the pig and in laboratory animals was elaborated. This autoimmune phenomenon called "immunologic mimicry" supports besides the special physiologic conditions as niche of defense a very successful evolutionary adaptation of the agent.

Age Factors↗